HRWC supports collaborative stormwater management
As human populations grew and settled within the watershed, they began to alter the way that water flows across the landscape. The addition of impervious surfaces such as roads, sidewalks and parking lots influence the flow of rainwater and snow-melt from the surrounding landscape to waterways. What people do with and to this stormwater ultimately has an impact on the quality of the Huron River and its tributaries. HRWC staff help local governments and residents in the watershed improve stormwater management and be good stewards of water resources.
The importance of stormwater management
Stormwater runoff collects and transports pollutants from the landscape; because these pollutants cannot be attributed to a specific source, they are known as nonpoint source pollutants, and they can be difficult to track and regulate. Stormwater runoff can contain a wide range of pollutants like solvents, automotive fluids, pet waste, lawn fertilizers, and household products. In the Huron River watershed, storm drains lead directly to streams and rivers without going through any treatment process. HRWC estimates that over 50% of many of the most prevalent river pollutants come from non-point sources and are collected as stormwater. In addition, as stormwater runs over hard surfaces like roads and roofs (impervious surfaces) it is not able to infiltrate, cool and filter through the ground. This runoff concentrates in large, warm, often polluted volumes during and following storms, resulting in faster flows that erode streambanks and carry soil and additional pollutants. Without stormwater infrastructure controls, this fast-flowing contaminated runoff results in surface water that is hotter, toxic to life and damaging to habitat.
Regulations and local governments
Beginning with the passage of the Clean Water Act (CWA)in 1972, lawmakers have been refining attempts to address the quality of stormwater runoff. Initially, the CWA only addressed direct discharge of pollutants from industrial facilities. Municipal stormwater was exempt. After a series of lawsuits and much congressional debate, the CWA was amended in 1987 to include regulations on stormwater discharge quality. At first, only industrial stormwater, large construction sites, combined sewers (systems transporting both sewage and stormwater runoff) and separate storm sewers in municipalities with populations greater than 100,000 were included (Phase I). However, in 1999 small construction sites and smaller municipal stormwater systems were brought under regulatory control as well (Phase II).
In general, municipalities are required to reduce pollutants in stormwater “to the maximum extent practicable.” This vague requirement is implemented through more specific requirements contained in stormwater management plans reviewed by state agencies (in Michigan, the of Environment, Great Lakes, and Energy). Rather than setting numeric pollutant limits, stormwater permits require six control measures: public participation, public education, illicit discharge detection and elimination, construction site controls, post-construction controls, and pollution prevention. To date, however, these regulations only cover storm systems in urbanized areas that are municipally owned. Private storm systems (e.g. private residential developments), rural and some suburban systems are not currently regulated.
How HRWC is helping
HRWC staff began working with local municipalities in the early 2000’s by developing watershed-wide stormwater plans and forming collaborative municipal working groups. HRWC currently works with collaborative groups in three counties: Livingston (the Livingston Watershed Advisory Group), Washtenaw (the Middle Huron Partners), and Wayne (the Alliance of Downriver Watersheds). HRWC assists these groups with public participation and education, technical advice and compliance, progress evaluation monitoring, and project or program development to help satisfy stormwater permit compliance. Each group meets on a quarterly basis to plan and share information, and the member municipalities provide funding for HRWC work each year.
What stormwater groups have accomplished
Over the years, HRWC has worked with municipal partners to improve stormwater management in a number of important ways.
- Public Education Plans include a variety of strategies for increasing public awareness about the watershed and actions that prevent pollution. The thousands of educational watershed community calendars that the groups produce and distribute annually represent one example. Surveys show that residents are more knowledgeable and willing to take steps at home to help reduce the impact of stormwater runoff on the watershed.
- Watershed Management Plans led to dozens of municipal projects that directly addressed a range of pollutant sources including homes, streets, parking areas and even the drainage systems themselves.
- Chemistry and flow monitoring results helped to identify target areas for pollutant reduction and have reported significant reductions in pollutants such as phosphorus and bacteria.
Stormwater regulations and controls have led to measurably higher-quality urban waterways, but there is still work to do. HRWC is encouraging more municipalities to develop stormwater utilities to pay for maintenance and improvements, and to install more green stormwater infrastructure (practices like rain gardens that encourage infiltration and filtration by plants). More is needed to capture and filter stormwater through the ground to continue to improve the quality of stormwater runoff and, in turn, the Huron River. Learn what you can do at home!
This blog post was originally published June 1st in the Huron River Report, Summer 2021.